Improvement in mining-machines



P. M. LEGHNER. Mining-Machine.

'No. 211,100. Patented Jan. 7, 1879.

N. PETERS. PHOTD-LI'KHOGRAP FRANCIS M. LEOHNER, OF WAYNESBURG, ASSIGNORTO THE LEGHNER MINING MACHINE 00.,

on COLUMBUS, OHIO.

IMPROVEMENT IN MINING-MACHINES.

Specification forming part ofLetters Patent No. 211,100, dated January7, 1879; application filed August 31, 1878.

To all whom it may concern:

Be it known that I, FRANCIS M. LEGHNER, of Waynesburg, in .the county of-Stark and State of Ohio, have invented certain new and usefulImprovements in Mining-Machines; and I do hereby declare that thefollowing is a full, clear, and exact description of the invention,which will enable others skilled in the art to which it appertains tomake and use the same, reference being had to the accompanying drawings,and to letters of reference marked thereon, which form a part of thisspecification.

Figure l is a plan view of a portion of a cutfer-bar h avin g myimprovements applied thereto. Fig. 2 is a transverse vertical sectiontaken'on line 00 m, Fig. 1. Fig. 3 is a vertical section on line g y,Fig. l; andFig. 4 is a detached view of one of the driving-chain links.

Like letters of reference indicate simila parts in all the figures.

This invention consists in improvements upon the cutters, thecutter-bar, and the chain which drives the cutter-bar in a machine formining coal, and is an improvement upon the mining-machines heretoforepatented to me.

Ais the cutter-bar,substantially rhomboidal in cross-section except atsuch points as are traversed by the chains and other places where it ismounted upon the sliding carriers, at which points it is rounded to fitthe box in which it turns. Upon opposite sides of this bar are securedthe cutter-sectionsB B, the cutting-teeth B being arranged to cut outthe ridges left by the teeth B, as will be readily understood. Thesecutters are adj ustably secured to the cutter-bar by means of set-screwsor bolts 1), which pass through slots in the cutter-plates; and it willbe observed that the shape of the cutter-bar in cross-section is such asto give wide faces upon which to secure the cutters.

The cutter-bar is provided with lugs to at suitable distances from theends of the bar to engage with the driving-chain; and it will be seenthat my peculiar construction of barpossesses some advantages over'thoseheretofore used-for instance, by making the portions traversed by thechain square in cross-section I am enabled to use a chain composed oflinks of equal length, and provide that each lug shall be acted upon atan equal distance from the center of the bar, thus applying the powerwith uniformity; while by making the portions of the bar which areoccupied by the cutters rhomboidal in cross-section I am enabled tofurnish wide bearing-surfaces to which to attach them (the cutters); andby constructing parts of the shaft with the long sides or the wide sidesat right angles in cross-section to other wide sides or faces I amenabled to arrange the cutters upon all four sides of the shaft, thusinsuring a nearly continuous cutting action and great steadiness in themovements of the cutting devices. Each side or face of each lug isformed upon the arc of a circle struck from about the center of theopposite side of the same lug, for a purpose which will soon beexplained.

The links of the chain are formed of rectangular bars of metal 0 G D I),connected at their ends by means of pivots E, which pass throughperforations in the ends of the links, upon each of which pivots ismounted a frictionroller, F, between the ends of the links D D, thediameter of these friction rollers being such that they project a littlebeyond the ends of the adjacent links. These friction-rollers serve thepurpose of properly spacing the links D D, and also perform. anotherfunction, to be hereinafter set forth.

Each chain link is chamfered or beveled upon one side to form a knife orcutting edge, which is indicated at c and 61, these knifeedges beingconstructed upon the inner faces of the links. By inner faces I mean thefaces which are next to the cutter-bar as the chain wraps the bar.

I have found in using chains the links of which are of the samethickness upon both edges that in operating my machine, especially whencutting the slate, the fine dust is sometimes packed upon-the cutter-barby the chain, thus forming a coating upon the bar and producing anenlargement at the points traversed by the chain to such an extent as toincrease its tension and seriously interfere with drivin g the cutters;but by using links with knifeedges, I find that the difficulty isentirely obviated, as the cutting action of said edges wholly preventsany accumulation or packing ing to the faces of the lugs a being formedin of slate or other material at these points.

By an examination of Fig. 3 of the drawings the operation of thefriction-rollers F will be readily understood, as it will be seen that,ow-

arcs of circles, the friction-rollers traverse the lugs easily, althoughin closecontact therewith, as the cutter-bar is revolved; hence anyunsteadiness or backlashing of the cutter-bar is prevented by the closecontact of the friction-roller with the lugs during their engagement.

Each lug a is provided with a cutting spur or tooth, a, (see Fig. 1,) toremove the coal as it advances, leaving but a thin wall of coal uncut infront of each link of the chain.

I have shown in my patent of January 30, 1877, N 0. 186,854, aconstruction of chain and cutter-shaft which is intended to secure someof the results aimed at in this invention-that is to say, steadiness ofmotion and certainty of operation of the cutters.

In my former patent I showed a cutter-bar having recesses formed in itssides and a chain the links of which were provided centrally withprojecting lugs which took into the re cesses; but my presentconstruction possesses many advantages over the former one, in that, forone thing, I am enabled to mount friction. rollers on the pivots whichunite the ends of the chain-links, the rollers engaging with the lugs onthe bar 5 and, again, the use of lugs on the bar enables me to useknife-edged links 0 D, which I could not construct with lugs projectingfrom the knife-edge, because there is not thickness enough of metal uponthe under edges to support lugs at those points.

What I claim is- 1. The herein-described chain consisting of links 0 O DD, pivots E, and friction-rollers I substantially as set forth.

2. The cutter-shaft provided with lugs at, having their engaging facesformed in arcs of circles, in combination with the chain provided withfriction-rollers F, substantially as set forth.

Amining-machine driving-chain thelinks of which are constructed withbeveled edges or cutting-edges, substantially as described.

4. A cutter-bar for a mining-machine having sections which are square incross-section to receive the driving-chain, and having other sectionswhich are rhomboidal in cross-section to receive the cutters,substantially as set forth.

5. A cutter-bar for a mining-machine having sections which arerhomboidal in crosssection to receive the cutters, and having othersections also rhomboidal in cross-section, but having their under facesarranged in planes at right angles to the planes of the wider faces ofthe adjoining sections, substantially as set forth.

In testimony that I claim the foregoing as my own I affix my signaturein presence of two witnesses.

FRANCIS M. LEOHNER. Witnesses:

H. H. DOUBLEDAY, THos. J. FORD.

